WO2023005856A1

WO2023005856A1 - Communication method and apparatus

Info

Publication number: WO2023005856A1
Application number: PCT/CN2022/107545
Authority: WO
Inventors: 杜瑞; 朱翔; 刘辰辰; 狐梦实; 韩霄; 杨讯; 张云; 李杨
Original assignee: 华为技术有限公司
Priority date: 2021-07-30
Filing date: 2022-07-22
Publication date: 2023-02-02
Also published as: CN115696389A

Abstract

The present application provides a communication method and apparatus, being capable of increasing the effective amount of information in a CSI feedback matrix, facilitating a transmitting end to extract the attribute information of a target object, and improving a sensing capability for the target object. The method comprises: a first device receives at least one channel detection frame from a second device, and determines at least one first CSI matrix H₁ according to the at least one channel detection frame, wherein H₁ is used for indicating a channel state, and the channel detection frame has one-to-one correspondence to H₁; then, the first device performs feature value decomposition on a covariance matrix R_HH of H₂ to obtain a feature vector matrix U and a feature value matrix ∑, wherein H₂ is determined according to H₁, and H₂ is a CSI matrix corresponding to any one sub carrier; and the first device determines, according to H₂, U, and ∑, a second CSI matrix V corresponding to H₁, and feeds back at least one V corresponding to at least one H₁ to the second device, wherein the at least one V is used for determining the attribute information of a target object.

Description

Communication method and device

This application claims the priority of a Chinese patent application filed with the State Intellectual Property Office on July 30, 2021, with application number 202110875718.5, and the title of the invention is “Communication Method and Device”, the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the technical field of communication, and in particular to a communication method and device.

Background technique

Wireless local area network (wireless local area network, WLAN) sensing (sensing) is a technology that uses wireless signals to sense target objects. Target objects refer to things in the surrounding environment, such as people and objects. Based on the ability to measure or sample the environment over the radio, WLAN sensing provides each communication path between two physical devices with the opportunity to extract information about its surroundings. At present, WLAN devices are widely deployed in today's society, so WLAN sensing has a very broad application prospect.

WLAN sensing can perform target object perception based on existing standards, and beamforming (beamforming) technology is defined in existing standards (for example: 802.11ac protocol). In this technology, the sender can rely on the result of channel estimation (CE) fed back by the receiver, that is, the channel state information (CSI) feedback matrix, to generate a steering matrix (steering matrix), in order to Improve the communication performance between the sender and receiver.

However, in the existing schemes for generating the CSI feedback matrix, the phase information cannot be retained in the CSI feedback matrix, and the phase information is crucial for extracting the attribute information of the target object (for example: target distance, target angle, target Doppler, etc.) important. For example, the target angle can be used to determine the target object's direction, the Doppler frequency is caused by the target object's motion, and thus the target Doppler can be used to determine the target object's velocity. However, the transmitting end cannot extract the attribute information of the target object according to the reconstructed CSI feedback matrix, and thus cannot effectively perceive the target object.

Contents of the invention

The embodiments of the present application provide a communication method and device, which can increase the amount of effective information in the CSI feedback matrix, facilitate the sending end to extract attribute information of the target object, and improve the perception ability of the target object.

In order to achieve the above object, the application adopts the following technical solutions:

In a first aspect, a communication method is provided, and the method includes: a first device receives at least one channel detection frame from a second device. The first device determines at least one first channel state information CSI matrix H ₁ according to at least one channel sounding frame, where H ₁ is used to indicate a channel state, and the channel sounding frames correspond to H ₁ one by one. _The dimension of H1 is N _r ×N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the first device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , Both K are positive integers; the first device performs eigenvalue decomposition on the covariance matrix R _HH of H ₂ to obtain an eigenvector matrix U and an eigenvalue matrix Σ. Wherein, H ₂ is determined according to H ₁ , and H ₂ is a CSI matrix corresponding to any subcarrier; the first device determines a second CSI matrix V corresponding to H ₁ according to H ₂ , U, and Σ. The first device feeds back at least one V corresponding to at least one H ₁ to the second device, and the at least one V is used to determine attribute information of the target object.

Based on the above technical solution, the first device can determine the first CSI matrix H ₁ used to indicate the channel state according to the received at least one channel detection frame, and then the first device performs eigenvalue decomposition on H ₂ to obtain the eigenvector matrix U and Eigenvalue matrix Σ, where H ₂ is determined according to H ₁ , and H ₂ is the CSI matrix corresponding to any subcarrier. Then the first device can determine the second CSI matrix V corresponding to H ₁ according to H ₂ , U, and Σ, and the obtained V contains phase information, and feeds back at least one V corresponding to H ₁ to the second device, At least one V is used to determine attribute information of the target object. The V matrix reconstructed by the second device also includes phase information, and the attribute information of the target object can be extracted according to the phase information, thereby improving the perception ability of the target object.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

In a possible design, the column vector u _s in U and the column vector v _s in V satisfy the following conditions:

Among them, σ _s is the singular value corresponding to v _s , σ _s is the arithmetic square root of the corresponding eigenvalue in Σ, s is an integer from 1 to m, m is the number of column vectors in V, and m is a positive integer. Since Σ is a real number matrix, σ _s is the arithmetic square root of the corresponding eigenvalue in Σ, σ _s does not contain phase information, and U matrix contains part of phase information (for example: in the case of only a single target object, U The matrix includes phase information for extracting target angles. In the case of multiple target objects or multipaths, the U matrix includes phase information for extracting target angles, and the two-by-two relationship between multiple target objects or multipaths Product information), correspondingly, the column vector u _s in the U matrix also contains part of the phase information, and contains the original phase information in H ₂ , so the relevant phase information is retained in the v _s , and the same in the V matrix Relevant phase information is retained, and the phase information can be used to subsequently extract attribute information of the target object.

In a possible design, the conditions for obtaining the column vectors in U include: assigning b to the a-th element in each column vector in U, where a is a positive integer and b is a real number. Since the phase information used to extract the target distance and the phase information used to extract the target Doppler need to be determined according to at least two V matrices, during the process of solving the at least two V matrices according to H ₂ , U and Σ, the U matrix The solution of each column vector needs to meet the conditions in the design, so as to ensure that the V matrix obtained by the solution contains effective information for extracting the target distance and effective information for extracting the target Doppler.

In a possible design, the attribute information of the target object includes a target distance, and the target distance is the sum of the distance between the target object and the first device, and the distance between the target object and the second device. Wherein, the target distance is determined by at least two Vs corresponding to _one H1.

In a possible design, the attribute information of the target object further includes a target angle, and the target angle includes a launch angle between the second device and the target object. Among them, the target angle is determined by a V.

In a possible design, the attribute information of the target object also includes target Doppler, and the target Doppler is the difference between the frequency at which the first device receives the channel detection frame through the target object and the frequency at which the second device sends the channel detection frame. Wherein, the target Doppler is determined by at least one V corresponding to at least two H ₁ .

In one possible design, a column vector in V corresponds to a target object.

In a possible design, after the first device receives at least one channel detection frame from the second device, the method further includes: the first device receives at least one trigger frame from the second device, and the at least one trigger frame is used to indicate that the first device V is determined from H ₂ , U, and Σ. Based on this design, the second device indicates to the first device to inform the first device to use the method provided by the embodiment of this application to solve V, which can increase the amount of effective information in the CSI feedback matrix, and facilitate the second device to extract the target object attribute information to improve the perception of the target object.

In a second aspect, a communication method is provided, and the method includes: a second device sending at least one channel detection frame to a first device. The second device receives at least one second CSI matrix V corresponding to at least _one H1 from the first device, at least one V is used to determine the attribute information of the target object, at least _one H1 is determined according to at least _one channel detection frame, and H1 is used for Indicates the channel status, and the channel detection frame corresponds to H ₁ one by one. _The dimension of H1 is N _r ×N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the first device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , K are all positive integers. V corresponding to H ₁ is determined by H ₂ , U and ∑, U is the eigenvector matrix of the covariance matrix R _HH of H ₂ , ∑ is the eigenvalue matrix of R _HH , H ₂ is determined according to H ₁ , and H ₂ is any one The CSI matrix corresponding to the subcarrier.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

Among them, σ _s is the singular value corresponding to v _s , σ _s is the arithmetic square root of the corresponding eigenvalue in Σ, s is an integer from 1 to m, m is the number of column vectors in V, and m is a positive integer.

In a possible design, the conditions for obtaining the column vectors in U include: assigning b to the a-th element in each column vector in U, where a is a positive integer and b is a real number.

In one possible design, a column vector in V corresponds to a target object.

In a possible design, before the second device receives at least one second CSI matrix V corresponding to at least _one H1 from the first device, the method further includes: the second device sends at least one trigger frame to the first device, at least one The trigger frame is used to instruct the first device to determine V according to H ₂ , U and Σ.

In a third aspect, a communication device is provided, including: a transceiver unit configured to receive at least one channel detection frame from a second device. A processing unit, configured to determine at least one first channel state information CSI matrix H ₁ according to at least one channel sounding frame, H ₁ is used to indicate the channel state, and the channel sounding frame is in one-to-one correspondence with H ₁ ; the dimension of H ₁ is N _r × N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the communication device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , and K are all positive integers. The processing unit is also used to perform eigenvalue decomposition on the covariance matrix R _HH _of _H2 to obtain the eigenvector matrix U and the eigenvalue matrix Σ; wherein, _H2 is determined according to H1, and _H2 is the CSI corresponding to any subcarrier matrix. The processing unit is further configured to determine a second CSI matrix V corresponding to H ₁ according to H ₂ , U, and Σ. The transceiver unit is further configured to feed back at least one V corresponding to at least one H ₁ to the second device, and the at least one V is used to determine attribute information of the target object.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

In a possible design, the attribute information of the target object includes the following target distance, where the target distance is the sum of the distance between the target object and the first device, and the distance between the target object and the second device. Wherein, the target distance is determined by at least two Vs corresponding to _one H1.

In one possible design, a column vector in V corresponds to a target object.

In a possible design, the transceiver unit is further configured to receive at least one trigger frame from the second device, and the at least one trigger frame is used to instruct the first device to determine V according to H ₂ , U, and Σ.

In a fourth aspect, a communication device is provided, including: a transceiver unit, configured to send at least one channel detection frame to a first device. The transceiver unit is further configured to receive at least one second CSI matrix V corresponding to at least _one H1 from the first device, at least one V is used to determine the attribute information of the target object, at least _one H1 is determined according to at least one channel detection frame, H ₁ is used to indicate the channel state, and the channel detection frame corresponds to H ₁ one by one. _The dimension of H1 is N _r ×N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the first device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , K are all positive integers. V corresponding to H ₁ is determined by H ₂ , U and ∑, U is the eigenvector matrix of the covariance matrix R _HH of H ₂ , ∑ is the eigenvalue matrix of R _HH , H ₂ is determined according to H ₁ , and H ₂ is any one The CSI matrix corresponding to the subcarrier.

Optionally, the transceiving unit may include a sending unit and a receiving unit, and the transceiving unit may be a whole or a separate unit, which is not limited in this embodiment of the present application.

Optionally, the communication device may further include a processing unit, where the processing unit is configured to generate at least one channel sounding frame.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

In one possible design, a column vector in V corresponds to a target object.

In a possible design, the transceiver unit is further configured to send at least one trigger frame to the first device, and the at least one trigger frame is used to instruct the first device to determine V according to H ₂ , U, and Σ.

According to a fifth aspect, a communication device is provided, and the communication device may be a first device, or may be a device in the first device. In one design, the device may include modules corresponding to one-to-one for executing the methods/operations/steps/actions described in the first aspect and any design thereof. The above-mentioned modules may be hardware circuits, or software, or may be realized by a combination of hardware circuits and software.

According to a sixth aspect, a communication device is provided, and the communication device may be a second device, or may be a device in the second device. In one design, the device may include modules corresponding to one-to-one for executing the methods/operations/steps/actions described in the second aspect and any design thereof. The above-mentioned modules may be hardware circuits, or software, or may be realized by combining hardware circuits with software.

In a seventh aspect, a communication device is provided. The communication device may be a first device, or may be a chip or a chip system disposed inside the first device. The communication device includes a processor and a transceiver, and the processor is configured to perform the determination operation, the eigenvalue decomposition operation, etc. in the communication method involved in any design of the first aspect above. The transceiver is used to receive the control of the processor, and execute the transceiving operation in the communication method involved in any design of the first aspect above. The transceiver can be a transceiver circuit or an input/output port. In the embodiment of the present application, the transceiver may also be an antenna.

In a possible design, the communication device described in the seventh aspect may further include a memory. The memory is coupled with the processor and used to store computer programs. The computer program is used to be executed by the processor, so that the communication device executes the communication method described in any design of the first aspect.

In an eighth aspect, a communication device is provided, and the communication device may be a second device, or a chip or a chip system disposed inside the second device. The communication device includes: a transceiver. The transceiver is used to perform the transceiving operation in the communication method involved in any design of the second aspect above. The transceiver can be a transceiver circuit or an input/output port. In the embodiment of the present application, the transceiver may also be an antenna.

In a possible design, the communication device described in the eighth aspect may further include a processor. The processor is configured to perform the determining operation, generating operation, etc. in the communication method involved in any design of the second aspect above, for example: generating at least one channel sounding frame.

In a possible design, the communication device described in the eighth aspect may further include a memory. The memory is coupled with the processor and used to store computer programs. The computer program is configured to be executed by the processor, so that the communication device executes the communication method described in any design of the second aspect above.

In a ninth aspect, a computer-readable storage medium is provided, the computer-readable storage medium includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes any design in the first aspect to the second aspect The communication method involved.

In a tenth aspect, a computer program product is provided, the computer program product includes: a computer program or an instruction, when the computer program or instruction is run on a computer, the computer is made to execute any one of the designs involved in the first aspect to the second aspect communication method.

In an eleventh aspect, a chip is provided, and the chip includes a processing circuit and transceiving pins. Optionally, the chip also includes a memory. Wherein, the processing circuit is configured to perform the determination operation, the eigenvalue decomposition operation, etc. in the communication method involved in any possible design in the first aspect. The transceiving pins are used to accept the control of the processing circuit, and perform the transceiving operation in the communication method involved in any possible design in the first aspect. The memory is used for storing instructions, and the instructions are invoked by the processor to execute the communication method involved in any possible design of the first aspect.

In a twelfth aspect, a chip is provided, and the chip includes transceiver pins. Optionally, the chip also includes processing circuits and memory. Wherein, the processing circuit is configured to perform the determining operation, generating operation, etc. in the communication method involved in any possible design in the second aspect. The sending and receiving pins are used to accept the control of the processing circuit, and perform the sending and receiving operation in the communication method involved in any possible design in the second aspect. The memory is used to store instructions, and the instructions are invoked by the processor to execute the communication method involved in any possible design of the second aspect.

In a thirteenth aspect, a communication system is provided, including: a first device and a second device. Wherein, the first device is configured to execute the communication method involved in any design of the first aspect above. The second device is configured to execute the communication method involved in any design of the second aspect above.

Wherein, the technical effect brought about by any design in the second aspect to the thirteenth aspect can refer to the technical effect brought about by the corresponding design in the first aspect, and will not be repeated here.

Description of drawings

FIG. 1 is a schematic flow chart of feeding back CSI information provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of a communication system architecture provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of an emission angle and an acceptance angle provided by an embodiment of the present application;

FIG. 4 is a schematic flowchart of a communication method provided in an embodiment of the present application;

FIG. 5 is a schematic diagram of a frame structure of a trigger frame provided by an embodiment of the present application;

Fig. 6 is a schematic diagram of a Common Info field provided by the embodiment of the present application;

FIG. 7 is a schematic diagram of another Common Info field provided by the embodiment of the present application;

FIG. 8 is a schematic diagram of a frame structure of another trigger frame provided by an embodiment of the present application;

Fig. 9a is a schematic diagram 1 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 9b is a schematic diagram 1 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 9c is a schematic diagram 1 of a simulation result for extracting Doppler information in a CSI feedback matrix obtained by using an existing scheme;

Fig. 9d is a schematic diagram 2 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 9e is a schematic diagram 2 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 9f is a schematic diagram 2 of the simulation result of extracting Doppler information in the CSI feedback matrix obtained by using the existing scheme;

FIG. 10a is a schematic diagram of a simulation result for extracting distance information in a CSI feedback matrix obtained by using the scheme provided by the embodiment of the present application;

Fig. 10b is a schematic diagram 1 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the scheme provided by the embodiment of the present application;

FIG. 10c is a schematic diagram of a simulation result 1 of extracting Doppler information in the CSI feedback matrix obtained by the solution provided by the embodiment of the present application;

Fig. 10d is a schematic diagram 2 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the scheme provided by the embodiment of the present application;

Fig. 10e is a schematic diagram 2 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 10f is a schematic diagram 2 of the simulation result of extracting the Doppler information in the CSI feedback matrix obtained by the solution provided by the embodiment of the present application;

Fig. 11a is a schematic diagram 3 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11b is a schematic diagram 3 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11c is a schematic diagram 3 of the simulation result of extracting the Doppler information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11d is a schematic diagram 4 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11e is a schematic diagram 4 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11f is a schematic diagram 4 of the simulation result of extracting Doppler information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11g is a schematic diagram 5 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11h is a schematic diagram 5 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by using the existing scheme;

Fig. 11i is a schematic diagram 5 of the simulation result of extracting Doppler information in the CSI feedback matrix obtained by using the existing scheme;

Figure 12a is a schematic diagram of the third simulation result of extracting the distance information in the CSI feedback matrix obtained by using the scheme provided by the embodiment of the present application;

Figure 12b is a schematic diagram of the third simulation result of extracting the angle information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 12c is a schematic diagram 3 of the simulation result of extracting Doppler information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 12d is a schematic diagram 4 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 12e is a schematic diagram 4 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by adopting the solution provided by the embodiment of the present application;

Fig. 12f is a schematic diagram 4 of the simulation result of extracting the Doppler information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 12g is a schematic diagram 5 of the simulation result of extracting the distance information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

Fig. 12h is a schematic diagram 5 of the simulation result of extracting the angle information in the CSI feedback matrix obtained by adopting the solution provided by the embodiment of the present application;

FIG. 12i is a schematic diagram 5 of a simulation result for extracting Doppler information in the CSI feedback matrix obtained by using the solution provided by the embodiment of the present application;

FIG. 13 is a schematic structural diagram of a communication device provided by an embodiment of the present application;

FIG. 14 is a schematic structural diagram of another communication device provided by an embodiment of the present application.

Detailed ways

In the description of the present application, unless otherwise specified, "/" means "or", for example, A/B may mean A or B. The "and/or" in this article is just an association relationship describing associated objects, which means that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone These three situations. In addition, "at least one" means one or more, and "plurality" means two or more. Words such as "first" and "second" do not limit the number and order of execution, and words such as "first" and "second" do not necessarily limit the difference.

It should be noted that, in this application, words such as "exemplary" or "for example" are used as examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "for example" is not to be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete manner.

In the description of this application, "instructions" may include direct instructions and indirect instructions, as well as explicit instructions and implicit instructions. The information indicated by certain information (such as the indication information described below) is called the information to be indicated, and there are many ways to indicate the information to be indicated during the specific implementation process. For example, the information to be indicated may be indicated directly, wherein the information to be indicated itself or an index of the information to be indicated may be indicated. For another example, the information to be indicated may also be indicated indirectly by indicating other information, where there is an association relationship between the other information and the information to be indicated. For another example, only a part of the information to be indicated may be indicated, while other parts of the information to be indicated are known or agreed in advance. In addition, the indication of specific information can also be realized by means of the pre-agreed arrangement order of each information (for example, stipulated by the protocol), thereby reducing the indication overhead to a certain extent.

In the embodiment of the present application, sometimes a subscript such as W ₁ may be a clerical error into a non-subscript form such as W1. When the difference is not emphasized, the meanings they intend to express are consistent.

In addition, the network architecture and business scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute limitations on the technical solutions provided by the embodiments of the present application. With the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

First, for ease of understanding, related terms and concepts that may be involved in the embodiments of the present application are introduced below.

1. Beamforming

Beamforming is derived from a concept of adaptive antenna. The receiving end forms the required ideal signal by weighting and combining the signals received by multiple antenna elements. If beamforming technology is used, a multi-antenna system must be used, for example, a multiple input multiple output (MIMO) system, which can not only use multiple receiving antennas, but also multiple transmitting antennas. Due to the use of multiple antennas, the same spatial streams (spatial streams) corresponding to the wireless signal from the transmitter to the receiver are transmitted through multiple paths. A certain algorithm is used at the receiving end to process the signals received through multiple antennas, which can improve the signal-to-noise ratio.

The sending end sends a sounding signal to the receiving end, such as a null data packet (NDP), and the receiving end performs channel estimation and feeds back the result of the channel estimation, that is, the CSI matrix, to the sending end so that the sending end can generate guidance Matrix, in order to improve the performance of communication.

At present, the ways for the receiving end to feed back to the sending end include implicit feedback and explicit feedback. Implicit feedback means that the receiving end does not feed back the specific information of CSI, but feeds back a response packet, such as NDP, to the sending end. Estimate the specific information of CSI based on the received data packets. Display feedback means that the receiving end performs channel estimation, generates specific information of CSI, and feeds it back to the sending end.

Show feedback as the mainstream feedback method, as shown in Figure 1, the specific process includes: the sending end (for example: access point (access point, AP)) generates an NDP composed of a preamble, which includes a short training field (short training field, STF), long training field (long training field, LTF) and other training sequences, these training sequences are known fixed symbols, after the inverse fast Fourier transform of the orthogonal frequency division multiplexing (OFDM) signal After (inverse fast fourier transform, IFFT) modulation, the baseband digital signal can be obtained, and then digital-to-analog conversion and up-conversion modulation are performed on it, and then it becomes a radio frequency signal and sent to the air interface. The receiving end obtains NDP after down-conversion, sampling, and OFDM demodulation. Wherein, the sending end may send the NDP in a broadcast manner, and the receiving end (for example: STA1) obtains the channel matrix H after performing channel estimation according to the received NDP, and then obtains the channel matrix H _eff corresponding to each subcarrier according to H. Wherein, one channel may include multiple subcarriers, and one channel matrix H may correspond to multiple channel matrices H _eff . Exemplarily, as shown in FIG. 1 , the channel matrix corresponding to the kth subcarrier may be expressed as H _eff,k . The channel matrix may also be referred to as a CSI matrix. It should be noted that, without additional explanation, the channel matrix and the CSI matrix mentioned in this application have the same meaning, and are described here together. Wherein, the process of extracting subcarriers shown in FIG. 1 is optional, and the purpose of extracting subcarriers is to reduce the amount of information feedback.

According to the different feedback content in the displayed feedback, it can be divided into the following three feedback methods:

(1) Feedback the original CSI matrix, for example: the H matrix shown in Figure 1, or the H _eff,k matrix.

(2) Feedback an uncompressed beamforming matrix, for example: the V _k matrix shown in FIG. 1 .

(3) Feedback the angle value after the compressed Givens rotation (givens rotation), for example: the angle value φ and the angle value ψ shown in FIG. 1 .

2. CSI

The CSI is used to feed back the status of the current wireless channel. In a wireless fidelity (Wireless Fidelity, WiFi) protocol, measurement is performed for each OFDM subcarrier, and a CSI matrix corresponding to the OFDM subcarrier is obtained. The number of rows of the CSI matrix is the number of transmitting antennas, and the number of columns of the CSI matrix is the number of receiving antennas. Each element of the CSI matrix is a complex number containing real and imaginary parts.

3. Singular value decomposition (SVD)

SVD can represent a more complex matrix by multiplying several smaller and simpler sub-matrices. These small matrices describe the important characteristics of a complex matrix.

As shown in FIG. 1 , after the receiving end obtains the channel matrix H _eff on each subcarrier, it can be decomposed by SVD. Wherein, the dimension of the matrix is N _r ×N _sts , N _r is the number of receiving antennas, N _sts is the number of spatial streams, and both N _r and N _sts are positive integers.

Taking the kth subcarrier as an example, the channel matrix H _eff,k on the kth subcarrier can be decomposed into the form of formula 1.1 through SVD.

Wherein, in Formula 1.1, H _k Q _k =H _eff,k , H _k is the real channel matrix, the dimension is N _r ×N _t , N _t is the number of transmitting antennas, and N _r is a positive integer. Q _k is an orthogonal spatial stream mapping matrix, which is used to map the transmitted data to the transmitting antenna, and the dimension of Q _k is N _t ×N _sts .

For the sake of simplicity, this scheme uses Q _k as the unit matrix, and N _{t =} N _sts for analysis and description. At this time, H _k Q _k = H _k , that is, H _k = H _eff,k , so the dimension of H _eff,k is also N _r ×N _t . It can be understood that the SVD decomposition is performed on H _eff,k , that is, the SVD decomposition is performed on H _k . V _k is the CSI matrix that needs to be fed back to the sender,

is the conjugate transpose matrix of V _k . Among them, U _k and V _k are orthogonal matrices, ∑ _k is a diagonal matrix, and the elements on the diagonal are the singular values of the H _eff,k matrix.

For the kth subcarrier, the transmitting end can construct the steering matrix Q _steer,k according to the V _k matrix, and the steering matrix Q _steer,k can be used to modulate the transmitted signal, which can be expressed in the form of formula 1.2.

Q _steer,k = Q _k V _k 1.2

The transmitted signal s modulated by the steering matrix Q _steer,k shown in Equation 1.2 after the original transmitted signal _s ' can be expressed in the form of Equation 1.3.

s=Q _steer,k s' 1.3

After the modulated transmission signal s, that is, the precoded transmission signal s is transmitted through the channel, the signal r received by the receiving end can be expressed in the form of Equation 1.4.

After simplification,

Among them, n in formula 1.4 is noise.

The receiving end multiplies the received signal _r to the left

After the matrix can be obtained:

remember

but

r'=∑ _k s'+n' 1.7

It can be seen from Equation 1.7 that since ∑ _k is a diagonal matrix, the process of SVD decomposition is essentially the process of diagonalizing the channel matrix, that is, V _k after SVD decomposition of the channel matrix H _eff,k by the receiving end The matrix is fed back to the sending end, and the sending end constructs a steering matrix Q _steer,k according to the V _k matrix, and uses the Q _steer,k matrix to modulate the original sending signal, and after channel transmission, the signal received by the receiving end is equivalent to Then the original sent signal is obtained after being transmitted through a diagonalized channel matrix. Since each column in s' corresponds to a data stream, these multiple data streams are transmitted through a diagonalized channel matrix, which is equivalent to Two data streams are transmitted in parallel in this channel without interfering with each other. Therefore, realizing the diagonalization of the channel matrix is beneficial to improve the communication performance.

4. Givens rotation

In the compressed feedback method, the receiving end compresses the V _k matrix into a series of angle values through givens rotation, and then feeds these angle values back to the sending end to realize compressed feedback. The transmitting end can reconstruct the V _k matrix according to the received angle values, and complete MIMO precoding, so as to improve communication performance. Assuming that the dimension of the V _k matrix is N _r ×N _c , N _r is the number of rows of the V _k matrix, and N _c is the number of columns of the V _k matrix, the V _k matrix compressed by givens rotation can be expressed in the form of formula 1.8.

in,

is a N _r ×N _c diagonal matrix, as shown in Equation 1.9. 1 _i-1 represents a sequence of length i-1 and all elements in the sequence are 1.

is a generalized identity matrix whose matrix dimension is N _r ×N _c .

Among them, G _li (ψ) in Equation 1.8 is the givens rotation matrix, as shown in Equation 1.10,

is the transpose matrix of G _li (ψ).

Among them, I _i-1 in formula 1.9 and formula 1.10 is the identity matrix of order i-1, and I _li-1 in formula 1.10 and

are the identity matrix of order li-1 and order N _r -l respectively.

in Equation 1.8

is the givens rotation matrix, as shown in formula 1.11.

The foregoing is an introduction to related terms and concepts that may be involved in the embodiments of the present application, and details will not be repeated below.

At present, the use of SVD to decompose the channel matrix is to make the transformed channel matrix diagonal, and the process of solving the U _k matrix and V _k matrix is to solve the covariance matrix

and the covariance matrix

eigenvectors to achieve. in,

As shown in formula 1.12,

As shown in formula 1.13. The current method for solving the V _k matrix is to first solve the covariance matrix, and then perform eigenvalue decomposition on it, thereby obtaining each orthogonal vector in the V _k matrix, that is, each column vector.

Among them, the formula 1.12 in

and in Equation 1.13

Both are the covariance matrix of the channel matrix H _eff,k .

According to the principle formula of SVD decomposition

After simplifying Equation 1.12, we can get

The relationship between the matrix and the V _k matrix, each column vector in the V _k matrix is essentially

eigenvectors of . so yes

By performing eigenvalue decomposition, the V _k matrix can be obtained. same, yes

The U _k matrix can be obtained by performing eigenvalue decomposition. The channel matrix transformed by the V _k matrix and the U _k matrix can be diagonalized.

Since the channel matrix H _eff,k contains phase information for extracting attribute information (for example: target distance, target angle, target Doppler) of the target object. For ease of understanding, H _eff,k is expressed in the form of formula 1.14, where

is the phase information representing time delay and Doppler contained in H _eff,k ,

The matrix is equivalent to the H _{eff, k} matrix extracts the phase information representing the time delay and Doppler

remaining part after.

In the case of a single target, that is, in the case of one target object, when solving the covariance matrix for the channel matrix shown in Equation 1.14, the phase information of time delay and Doppler

is offset, but in the case of multiple targets, that is, in the case of multiple target objects, a pairwise multiplication term between multiple targets will be generated. Therefore, the V _k matrix and U _k matrix obtained by formula 1.12 and formula 1.13 can satisfy formula 1.15, that is, the equation 1.1 of SVD decomposition is not satisfied.

However, the V _k matrix and U _k matrix obtained by Equation 1.12 and Equation 1.13 can meet the requirements of beamforming. As shown in Equation 1.16, the channel matrix H _eff,k is also That is, after the channel matrix H _eff,k is transformed by the V _k matrix and U _k matrix solved by the above method, a diagonal matrix Λ _k will also be obtained, but the difference between the Λ _k matrix and the Σ _k matrix is that the Σ _k matrix is The elements on the diagonal are all real numbers, while the elements on the diagonal of the Λ _k matrix are complex numbers including phases.

The above introduction takes the kth subcarrier as an example. It should be noted that the method for solving the V matrix corresponding to any subcarrier is the same as the method for solving the V _k matrix corresponding to the kth subcarrier.

Therefore, how to improve the phase information included in the CSI feedback matrix V, that is, the amount of effective information, so that the sender can extract the attribute information of the target object from the reconstructed CSI feedback matrix V, and improve the perception of the target object Capacity is an urgent problem to be solved.

The technical solutions provided by the embodiments of the present application can be used to solve the above technical problems, and the technical solutions can be applied to various communication systems, for example: in the existing Institute of Electrical and Electronics Engineers (Institute of Electrical and Electronics Engineers, IEEE) 802.11 series standards Relevant standards (for example: 802.11n, 802.11ac, 802.11ax, 802.11be, etc.) of mainstream low-frequency bands (for example: 2.4GHz and 5GHz), relevant standards for high-frequency bands (for example: 60GHz) (for example: 802.11ad/directional multi-thousand Megabit (directional multi-gigabit, DMG), 802.11ay/enhanced directional multi-gigabit (enhanced directional multi-gigabit, EDMG)) and future WLAN standards.

The technical solution of the present application can also be applied to a cellular communication system, such as a fourth generation (4th generation, 4G) communication system, a fifth generation (5th generation, 5G) communication system, and the like.

The applicable scenarios of the technical solution of the present application include: a communication scenario between a first device and a second device, a communication scenario between a first device and a first device, and a communication scenario between a second device and a second device. The technical solution of this application is mainly introduced from the communication scenario between the first device and the second device, and technical solutions in other scenarios can be implemented by referring to the communication scenario between the first device and the second device.

Exemplarily, as shown in FIG. 2 , it is a schematic structural diagram of a communication system to which the communication method provided in the embodiment of the present application is applicable, and the communication system includes a second device and at least one first device.

Optionally, the above-mentioned second device may be a device located on the network side of the above-mentioned communication system and has a wireless transceiver function, or a chip or a chip system that may be provided in the device. The first device in the embodiment of the present application is an apparatus that provides services for the second device, which may be an access point (AP), for example, the second device may be a communication entity such as a communication server, a router, a switch, or a network bridge. , or, the second device may include various forms of macro base stations, micro base stations, relay stations, etc., of course, the second device may also be chips and processing systems in these various forms of devices, so as to implement the embodiment of the present application methods and functions. Moreover, with the continuous evolution of wireless local area network application scenarios, the second device can also be applied in more scenarios, such as sensor nodes in smart cities (for example, smart water meters, smart meters, smart air detection nodes), and smart homes. Smart devices (such as smart cameras, projectors, display screens, TVs, stereos, refrigerators, washing machines, etc.), nodes in the Internet of Things, entertainment terminals (such as AR, VR and other wearable devices), smart devices in smart offices (such as printers, projectors, etc.), Internet of Vehicles equipment in the Internet of Vehicles, and some infrastructure in daily life scenes (such as vending machines, self-service navigation consoles in supermarkets, self-service cashier equipment, self-service ordering machines, etc.).

Exemplarily, the first device is a device with a wireless communication function. The device may be a complete device, or may be a chip or a processing system installed in the complete device, and the device in which these chips or processing systems are installed may Under the control of these chips or processing systems, the methods and functions of the embodiments of the present application are realized. For example, the first device in the embodiment of the present application has a wireless transceiver function, which can be a station (station, STA), and can communicate with the second device or other devices. For example, the first device allows the user to communicate with the second device and then Any user communication device that communicates with the WLAN. For example, the first device may be a tablet computer, a desktop, a laptop, a notebook computer, an ultra-mobile personal computer (Ultra-mobile Personal Computer, UMPC), a handheld computer, a netbook, a personal digital assistant (Personal Digital Assistant, PDA), For user equipment that can be connected to the Internet such as mobile phones, or Internet of Things nodes in the Internet of Things, or smart devices, or vehicle communication devices in the Internet of Vehicles, etc., the first device can also be chips and processing systems in these terminals. In the embodiment of the present application, there is no special limitation on the specific forms of the first device and the second device, which are only illustrative descriptions here.

Optionally, the above-mentioned first device may be a device located on the network side of the above-mentioned communication system and has a wireless transceiver function, or a chip or a chip system that may be configured in the device. The second device may be a device with a wireless communication function, and the device may be a complete device, or a chip or a processing system installed in the complete device, and the devices installed with these chips or processing systems may Or under the control of the processing system, the methods and functions of the embodiments of the present application are implemented. This application is not limited to this.

It should be noted that the communication method provided by the embodiment of the present application can be applied between the first device and the second device shown in FIG. 2 , and the specific implementation can refer to the method embodiment described later, and will not be repeated here. .

It should be noted that the solutions in the embodiments of the present application can also be applied to other communication systems, and the corresponding names can also be replaced with names of corresponding functions in other communication systems.

It should be understood that FIG. 2 is only a simplified schematic diagram for easy understanding, and the communication system may also include other devices, which are not shown in FIG. 2 .

Before introducing the method provided in the embodiment of the present application, the simulation analysis process of the communication method provided in the embodiment of the present application will be described below.

Exemplarily, the channel response H _eff,k,i caused by the target object's target distance, target angle, target Doppler and other parameters can be expressed as Equation 1.17, and the channel response is also the channel matrix.

Among them, in formula 1.17, k represents the kth subcarrier, i represents the i-th pulse, that is, the i-th NDP, one NDP corresponds to one channel matrix H, and one NDP can be transmitted through multiple subcarriers (including sending and receiving) , the channel matrix H corresponding to one NDP may include channel information of multiple subcarriers, that is, one H may include multiple H _eff . L represents the number of target objects, τ _l represents the time delay corresponding to the l-th target object, and f _dl represents the Doppler frequency corresponding to the l-th target.

is the MIMO channel matrix corresponding to the lth target object, where

It can be expressed in the form shown in Equation 1.18.

In Equation 1.18, d is the antenna distance, θ _tl is the angle of departure (AOD) corresponding to the l-th target object, θ _rl is the angle of arrival (AOA) corresponding to the l-th target object, N _t is the number of transmitting antennas, N _r is the number of receiving antennas, and λ is the wavelength of the carrier frequency.

Exemplarily, as shown in Figure 3, θ _t is the emission angle corresponding to the target object, θ _r is the reception angle corresponding to the target object, Tx is the transmitting antenna, Rx is the receiving antenna, d _t is the distance between the two transmitting antennas Distance, d _r is the distance between the two receiving antennas.

If the CSI feedback matrix V is directly calculated through the channel matrix H _eff,k according to the above scheme, the target distance and the phase information corresponding to the target Doppler will be canceled. In the following, it is taken that the transmitting end and the receiving end include a line of sight (LOS) path and a target reflection echo as an example, and the target reflection echo may also be called a target reflection path.

Exemplarily, as shown in FIG. 3 , the LOS path refers to the path of the channel directly from the sending end to the receiving end, and the target reflection echo refers to the path of the channel from the sending end through the target object and then to the receiving end.

The covariance matrix R _HH of the channel matrix H _eff,k,i can be expressed as shown in formula 1.19.

In Equation 1.19,

is the conjugate transposition matrix of H _eff,k,i , R _los matrix, R _targ matrix, R _los-targ matrix, R _targ-los matrix can be expressed as Equation 1.20, Equation 1.21, Equation 1.22, Equation 1.23 respectively form.

in Equation 1.20

Represents the MIMO channel matrix corresponding to the LOS path,

for

The conjugate transpose matrix of .

in Eq. 1.21

Indicates the MIMO channel matrix corresponding to the target reflected echo,

for

The conjugate transpose matrix of .

Among them, τ _targ in Equation 1.22 and Equation 1.23 represents the time delay corresponding to the target reflection echo, τ _los represents the time delay corresponding to the LOS path, f _dtarg represents the Doppler frequency corresponding to the target reflection echo, and f _dlos represents the LOS path Corresponding Doppler frequency.

Assuming that the energy of the LOS path is much greater than the energy of the reflected echo of the target, the energy of the above R _los is the largest, and the R _los does not contain any linear phase on the subcarrier, that is, there is no phase used to determine the attribute information of the target object information. Therefore, the delay information (for example: τ _l ) and Doppler frequency (for example: f _dl ) in the above formula cannot be directly and effectively extracted in the dimensions of different subcarriers or different pulses.

Based on the above analysis, the embodiment of the present application provides a communication method, which can retain the phase information used to extract the attribute information of the target object in the CSI feedback matrix V, thereby improving the target perception capability. The method includes: the receiving end determines the CSI matrix H ₂ corresponding to each subcarrier according to the channel sounding frame received from the sending end, and then performs eigenvalue decomposition on the covariance matrix R _HH of H ₂ to obtain the eigenvector matrix U and the eigenvalue matrix Σ , and then determine V according to the U matrix and the Σ matrix. In this way, the V matrix obtained by solving contains phase information, so after the receiving end feeds the V matrix back to the sending end, the sending end can extract from the reconstructed V matrix Attribute information of the target object.

The communication method provided by the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

Exemplarily, FIG. 4 is a schematic flowchart of a communication method provided in an embodiment of the present application. This communication method may be applicable to the communication between the first device and the second device shown in FIG. 4 . As shown in Figure 4, the communication method includes the following steps:

S401. The second device sends at least one channel detection frame to the first device. Correspondingly, the first device receives at least a channel sounding frame from the second device.

Exemplarily, the channel detection frame may be an NDP frame, and the channel detection frame may be used for channel measurement. The second device may send the channel detection frame to the first device in a broadcast manner. Optionally, after the first device receives the channel sounding frame, it first removes the cyclic shift delay (cyclic shift delay, CSD) on each space-time stream (that is, the channel sounding frame), and then performs the subsequent steps.

S402. The first device determines at least one first CSI matrix H ₁ according to at least one channel sounding frame.

Wherein, the H ₁ is used to indicate the channel state, and H ₁ is also the channel matrix H mentioned above. There is a one-to- _one correspondence between channel sounding frames and H1. The one-to-one correspondence means that the first device can determine H ₁ corresponding to each channel detection frame according to each received channel detection frame, where each channel detection frame belongs to at least one of the above-mentioned channel detection frames .

For example: the first device may determine the first CSI matrix H ₁ ⁱ according to the received i-th channel sounding frame, where i is a positive integer, and the i-th channel sounding frame belongs to the above at least one channel sounding frame. The first device may also determine the first CSI matrix H ₁ ⁱ⁺¹ according to the i+1th channel sounding frame, where the i+1th channel sounding frame also belongs to the at least one channel sounding frame. In this application, the first CSI matrices H ₁ ⁱ , H ₁ ⁱ⁺¹ , etc. are represented by H ₁ , and each H ₁ corresponds to a channel detection frame, and each channel detection frame can be used to determine the corresponding to H ₁ . It should be understood that for different channel sounding frames, the specific content _of H1 corresponding thereto may be different.

Wherein, the dimension of H1 is N _r ×N _t ×K, N _t _is the number of antennas of the second device, that is, the number of transmitting antennas, and N _r is the number of antennas of the first device, that is, the number of receiving antennas. K is the number of subcarriers carrying the channel sounding frame, and N _t , N _r , and K are all positive integers. It should be noted that one channel sounding frame can be carried on multiple subcarriers, and _one H1 also corresponds to multiple subcarriers.

Optionally, the first device may determine the H ₁ corresponding to each channel sounding frame according to the received all channel sounding frames, or determine the H ₁ corresponding to this part of the channel sounding frames according to a part of all the received channel sounding frames, This application is not limited to this.

Exemplarily, the first device may obtain H ₁ through channel estimation.

S403. The first device performs eigenvalue decomposition on the covariance matrix R _HH of H ₂ to obtain an eigenvector matrix U and an eigenvalue matrix Σ.

Wherein, H ₂ can be determined according to H ₁ , H ₂ is the CSI matrix corresponding to any subcarrier, H ₂ is H _eff , the dimension of H ₂ is N _r ×N _t , and N _t is the antenna of the second device number, N _r is the number of antennas of the first device.

It should be understood that one H ₁ can correspond to multiple subcarriers, so for the multiple subcarriers corresponding to H ₁ , the H ₂ corresponding to any one of the subcarriers can be determined according to the H ₁ , so one H ₁ can correspond to A plurality of H ₂ , corresponding here can also be described as comprising.

Exemplarily, it is taken that H ₁ includes 4 subcarriers as an example, that is, in the case that the dimension of H ₁ is N _t ×N _r ×K, the value of K is 4. For these 4 subcarriers, each subcarrier corresponds to an H ₂ , for example: the first subcarrier corresponds to H ₂ ¹ , the third subcarrier corresponds to H ₂ ³ , H ₂ ¹ and H ₂ ³ can be based on the same H ₁ Determined, while H ₂ ¹ , H ₂ ³ , etc. are all represented by H ₂ in the application. It should be understood that for different subcarriers, the specific content of H ₂ corresponding thereto may also be different.

Optionally, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

Optionally, in the process of decomposing the R _HH eigenvalues and calculating the U matrix, the conditions for obtaining the column vectors in U include: assigning the a-th element in each column vector in U to b, where a is a positive integer, and b is a real number. It should be understood that this condition needs to be satisfied for each column vector in U. Here the column vector is also the feature vector. The following examples illustrate it in detail.

Exemplarily, assuming that the above H ₂ matrix is a 2×2 matrix, the covariance matrix R _HH of this matrix can be expressed in the form of Equation 1.24.

Decompose the eigenvalues of the covariance matrix R _HH . According to the knowledge of linear algebra, its eigenvalues can be expressed as the form shown in formula 1.25.

RU＝λU 1.25

Among them, U in formula 1.25 is the column vector matrix of the covariance matrix R _HH , and λ is the eigenvalue corresponding to the eigenvector matrix U.

Since H ₂ is a 2×2 matrix, correspondingly, U includes two column vectors: U ₁ and U ₂ , let U be expressed in the form of formula 1.26.

Among them, in formula 1.26, u ₁ and u ₂ can be referred to as elements in U ₁ , and u ₃ and u ₄ can be referred to as elements in U ₂ . Usually, when calculating the column vector, for the convenience of calculation, after obtaining the relationship between u ₁ and u ₂ , one element in u ₁ and u ₂ is often used as a reference item, and a constant 1 is assigned to it, so as to obtain the other One element, and then get U ₁ , and get U ₂ similarly. Exemplarily, if u ₂ =u ₄ =1, U ₁ and U ₂ can be obtained, as shown in formula 1.27.

where, in Equation 1.27,

is the conjugate of _C2 . Exemplarily, for solving U ₁ , no matter which element is taken as a reference item, the relationship between u ₁ and u ₂ will not be changed in essence, and for solving U ₂ , no matter which element is taken as a reference item, In essence, the relationship between u ₃ and u ₄ will not be changed, but the corresponding numerical solution will be changed proportionally. Therefore, for the finally obtained U, and according to U and V obtained by solving ∑, they always satisfy Equation 1.28.

H ₂ =U∑V ^H 1.28

Therefore, for the CSI matrix _H2 corresponding to a subcarrier, during the SVD decomposition process, when solving the column vector of the U matrix, the reference item adopted will not affect the decomposition, and the obtained matrix after decomposition can be Satisfy the above formula 1.28.

However, since the delay information is carried on multiple subcarriers of one channel sounding frame, and the Doppler information is carried on multiple channel sounding frames, it should be understood that the delay information and the Doppler information here are also phase information.

Therefore, in order to ensure the correct retention of delay information and Doppler information, in the case of performing SVD decomposition on the CSI matrix _H2 corresponding to different subcarriers in different channel sounding frames, when calculating the column vector in U, it is necessary to select The elements at the same position are used as reference items. For example, assuming that the a-th element in the first column vector in the U matrix is used as a reference item, then for other column vectors, the a-th element should also be selected as a reference item. And also need to assign the same value to these reference items. For example: You can use the first element of all column vectors in U as a reference item, and assign it a value of 1 to solve the column vectors in U.

S404. The first device determines the second CSI matrix V corresponding to H ₁ according to H ₂ , U, and Σ;

Wherein, there is a one-to-one correspondence between H ₂ and V, and since H ₁ can correspond to multiple H ₂ , H ₁ can correspond to multiple Vs.

Optionally, the column vector u _s in U and the column vector v _s in V satisfy the following conditions:

Wherein, σ _s is the singular value corresponding to v _s , σ _s is the arithmetic square root of the corresponding eigenvalue in Σ, s is an integer from 1 to m, m is the number of column vectors in V, and m is a positive integer.

Since Σ is a real number matrix, σ _s is the arithmetic square root of the corresponding eigenvalue in Σ, σ _s does not contain phase information, and U matrix contains part of phase information (for example: in the case of only a single target object, U The matrix includes phase information for extracting target angles. In the case of multiple target objects or multipaths, the U matrix includes phase information for extracting target angles, and the two-by-two relationship between multiple target objects or multipaths Product information), correspondingly, the column vector u _s in the U matrix also contains part of the phase information, and contains the original phase information in H ₂ , so the relevant phase information is retained in v _s , correspondingly, V Relevant phase information is also retained in the matrix, and this phase information can be used to subsequently extract attribute information of the target object.

S405. The first device feeds back at least one V corresponding to at least one H ₁ to the second device. Correspondingly, the second device receives at least one V corresponding to at least one H ₁ fed back by the first device.

Wherein, at least one V is used to determine the attribute information of the target object. V is an orthogonal matrix. Optionally, a column vector in V corresponding to a target object. Optionally, the V matrix can also be used for MIMO precoding (precoding) to achieve the purpose of channel diagonalization, thereby improving communication performance.

Optionally, the attribute information of the target object may include a target distance. The target distance is the sum of the distance between the target object and the first device and the distance between the target object and the second device. Exemplarily, the target distance is shown in FIG. 3 Indicates the distance of the reflected echo from the target. Specifically, since the delay information needs to be determined according to at least two subcarriers in a channel sounding frame, the target distance can be determined by at least two Vs corresponding to _one H1, that is, at least two subcarriers in a channel sounding frame The corresponding V is determined.

Optionally, the attribute information of the target object may further include a target angle, and the target angle includes a launch angle between the second device and the target object, such as θ _t shown in FIG. 3 . Wherein, the target angle can be determined by V corresponding to any subcarrier.

Optionally, the attribute information of the target object may also include target Doppler, where the target Doppler is the difference between the frequency at which the first device receives the channel detection frame through the target object and the frequency at which the second device sends the channel detection frame. Exemplarily, as shown in FIG. 3 , the target Doppler is the difference between the receiving frequency of the receiving end and the sending frequency of the sending end when the channel detection frame is transmitted through the target reflection echo. Wherein, the target Doppler may be determined by V corresponding to the same subcarrier in at least two channel sounding frames, where the same subcarrier refers to a subcarrier with the same frequency. For example: assuming that two channel sounding frames are taken as an example, and the V corresponding to the kth subcarrier in one of the channel sounding frames is selected, then the V corresponding to the kth subcarrier in the other channel sounding frame can also be selected, and then the two V determines the target Doppler.

Optionally, the first device may also use givens rotation to compress the V matrix into a series of angle values, and then feed back the compressed angle values to the second device.

Based on the above technical solution, the effective information amount in the CSI feedback matrix can be retained, which facilitates the extraction of attribute information of the target object and improves the perception ability of the target object.

Optionally, before step S405 shown in FIG. 4, the following steps (not shown in the figure) are also included:

S406. The second device sends at least one trigger frame to the first device. Correspondingly, the first device receives at least one trigger frame from the second device.

Wherein, the trigger frame is used to instruct the first device to determine V according to H ₂ , U and Σ. The trigger frame may also have other names, which are not limited in this application. Optionally, this step may also be located before step S404, and this step may also be located after step S401, which is not specifically limited in this application.

Exemplarily, as shown in FIG. 5 , it is a frame format of a trigger frame provided by the embodiment of the present application. Among them, in 802.11ax, the specific structure of the Common Info field in the frame format is shown in Figure 6. In 802.11be, the specific structure of the Common Info field in this frame format is shown in Figure 7.

Exemplarily, this embodiment of the present application may indicate that the trigger frame is a polling for a perceptual beamforming report according to the content shown in Table 1, and then be used to instruct the first device to determine V according to H ₂ , U, and Σ.

In a possible implementation manner, a reserved value in the trigger type field may be used to indicate, for example, any one or more values from 8 to 15. Exemplarily, as shown in Table 1, when the Trigger type is 8 in the field shown in FIG. 6 or FIG. The first device is instructed to determine V from _H2 , U, and Σ. Exemplarily, the Trigger type may also use other reserved values to indicate that the trigger frame is a trigger frame for the polling of the perceptual beamforming report, for example, values from 9 to 15, etc., which are not specifically limited in the present application.

In another possible implementation manner, the value already used in the trigger type field may be used to indicate, for example: any one or more values in 0-7. Exemplarily, as shown in Table 1, the value 1 can be used to indicate, and when the current Trigger type is 1, the corresponding beamforming report polling is modified to the perceptual beamforming report polling to indicate the trigger frame The trigger frame is polled for the cognitive beamforming report, that is, the trigger frame is used to instruct the first device to determine V according to H ₂ , U, and Σ.

Table 1

Exemplarily, as shown in FIG. 8, another frame format of a trigger frame is provided for the embodiment of the present application, and the trigger frame may also be called a beam refinement protocol (beam refinement protocol, BRP) request (request) frame.

When the Feedback Type field is 0, it indicates that the current multi-user (multi user, MU) scenario is present. In the embodiment of the present application, when the Feedback Type field is 1, the bit position can be set to 1 to indicate that the trigger frame is polling for the perceptual beamforming report, that is, the trigger frame is used to instruct the first device according to the H ₂ , U and Σ determine V.

In a possible implementation manner, it may be indicated by a reserved field. Exemplarily, as shown in Table 2, it can be indicated by the B91 field. When the B91 field is 1, it is used to indicate that the first device determines V according to H ₂ , U, and Σ. When the B91 field is 0, it is reserved field. It can also be indicated by other reserved fields, for example: any one or more fields in B92 to B95.

In another possible implementation manner, an indication may also be made by modifying a currently used field. Exemplarily, the B87 field may be modified to instruct the first device to determine V according to H ₂ , U, and Σ. Optionally, other used fields may also be modified, which is not limited in this application.

It should be noted that the cognitive beamforming report polling is only a name, which is not enough to limit its function, and there may be other names, which are not limited in this application.

Table 2

B91比特数值B91 bit value	含义meaning
11	感知波束形成报告轮询Cognitive Beamforming Report Polling
00	预留reserve

The above mainly explains how to determine the V matrix in detail. The method for feeding back the V matrix from the first device to the second device will be described in detail below. For example, the first device can feed back the V matrix to the second device in the following manner .

Method 1: Using a noncompressed beamforming report (noncompressed beamforming report), wherein in this method, the first device can sequentially quantize and encode the CSI feedback matrix V on each subcarrier in the order of the real part and the imaginary part, and then follow the table 3. Table 4 shows the frame structure of the data frame, forming a data frame to feed back to the second device, wherein Table 3 shows the frame structure of the data frame when the signal bandwidth is 20MHz, and Table 4 shows the data when the signal bandwidth is 40MHz The frame structure of the frame. It should be noted that mode 1 exists in the existing standard 802.11n, but does not exist in 802.11ac and subsequent standards.

table 3

Exemplarily, as shown in Table 3, the CSI feedback matrix V corresponding to subcarriers (for example: subcarrier-28, subcarrier 1, etc.) can be quantized and coded into 2×N _b ×N _c ×N _r bits .

Table 4

Exemplarily, as shown in Table 4, the CSI feedback matrix V corresponding to subcarriers (for example: subcarrier-58, subcarrier 2, etc.) can be quantized and coded as 2×N _b ×N _c ×N _r bit.

Mode 2: using a compressed beamforming report (compressed beamforming report), in this mode, the first device compresses the CSI feedback matrix V into a series of angle values, for example: using the formula shown in formula 1.8 to compress V into a series of angle values value, this series of angle values includes angle value φ and angle value ψ. Then φ and ψ are quantized and coded according to Table 5, and finally according to the frame structure of the data frame shown in Table 6 or Table 7, a data frame is formed and fed back to the second device. Wherein, Table 6 shows the frame structure of the data frame when the signal bandwidth is 20 MHz, and Table 7 shows the frame structure of the data frame when the signal bandwidth is 40 MHz. Exemplarily, mode 2 exists in current standards 802.11ax and 802.11be.

table 5

Exemplarily, as shown in Table 5, b _ψ can be used to quantize the angle value ψ, and b _φ can be used to quantize the angle value φ.

Table 6

Exemplarily, as shown in Table 6, the CSI feedback matrix V corresponding to subcarriers (for example: subcarrier-28, subcarrier 1, etc.) can be quantized and coded as N _a ×(b _ψ +b _φ ) /2 bits.

Table 7

Exemplarily, as shown in Table 7, the CSI feedback matrix V corresponding to subcarriers (for example: subcarrier-58, subcarrier 2, etc.) can be quantized and coded as N _a ×(b _ψ +b _φ ) /2 bits.

It should be noted that the above-mentioned related introduction to the method for feeding back the V matrix from the first device to the second device belongs to the low-frequency scenario, and the high-frequency scenario will be introduced below.

In high-frequency scenarios, only method 2 is included. Exemplarily, in the 802.11ay protocol, 1 bit is used to indicate the feedback mode, as shown in the first column of Table 9, 0 is single carrier (single carrier, SC) physical layer (physical layer, PHY) uncompressed feedback , 1 is OFDM PHY compression feedback. When the value of the feedback type subfield in Table 9 is 1, the first device compresses V into a series of angle values, for example: using the formula shown in formula 1.8 to compress V into a series of angle values, the series of angles The values include the angle value φ and the angle value ψ. Then φ and ψ are quantized and encoded according to Table 8, and finally according to the frame structure of the data frame shown in Table 9, and the value of the feedback type field is 1, a data frame is formed and fed back to the second device.

Table 8

Table 9

Exemplarily, as shown in Table 9, for channels of different modes, the corresponding numbers of quantized coding bits are different. When the value of the feedback type field is 1, that is, when the V matrix is fed back in mode 2, the corresponding number of quantized coding bits is different for channels of different modes. For example, for channels with bandwidths of 2.16GHz and 4.32GHz, the number of For channels such as 2.16+2.16GHz, 4.32+4.32GHz, etc., the angle values in the V matrix can be respectively quantized and coded into different bits.

The method for reconstructing each V matrix and extracting attribute information of the target object from the second device after receiving the above data frame fed back by the first device will be described in detail below. It should be noted that this method is applicable to both the above-mentioned low-frequency scene and high-frequency scene.

(1) Extracting the target distance: Assume that the number of column vectors in the V matrix is recorded as N _c , and each column vector corresponds to a target object or LOS path, for example: in the V matrix corresponding to the largest eigenvalue in the eigenvalue matrix Σ The first column vector corresponds to the LOS path. For the different subcarriers contained in any channel detection, select the elements at the same position for each column vector in the V matrix in turn, and sample them, for example: for each column vector, select the nth element , n is a positive integer. Then fast Fourier transform (FFT) processing is performed on the sample, and the distance corresponding to the peak in the obtained spectrogram is the target distance. Since sampling and FFT processing are prior art, the present application will not repeat them.

(2) Target angle: According to the conclusion in the matrix analysis theory, each column vector in the V matrix can be expressed as a linear combination of the column vectors in the H matrix. However, the linear phase difference for extracting the target angle is reserved between the column vectors in the H matrix, that is, the phase information for extracting the target angle is retained in the H matrix. Therefore, in the case that the V matrix can be obtained by linear combination of the column vectors in the H matrix, the phase information used to extract the target angle is also preserved in the V matrix. For the V matrix corresponding to any subcarrier, the multi-signal classification algorithm (multiple signal classification, MUSIC) processing is performed on each column vector in the V matrix in turn, and the target angle value of each target object can be roughly estimated, and then After solving the covariance of the V matrix, and performing MUSIC processing on it, the precise target angle value of each target object can be obtained, and the angle corresponding to the peak in the obtained spectrogram is the target angle. Since MUSIC processing is a prior art, this application will not repeat it.

(3) Target Doppler: Assume that the number of column vectors in the V matrix is recorded as N _c , and each column vector corresponds to a target object or LOS path, for example: in the V matrix corresponding to the largest eigenvalue in the eigenvalue matrix Σ The first column vector of corresponds to the LOS path. For the same subcarrier in different channel sounding frames, the elements at the same position are selected for each column vector in the V matrix in turn, and samples are taken, and then the samples are processed by Fast Fourier Transform (FFT). The corresponding Doppler frequency is the target Doppler.

The following introduces the simulation results of extracting the attribute information of the target object from the V matrix obtained from the technical solution provided by the embodiment of the present application, and the simulation results of extracting the attribute information of the target object from the V matrix obtained from the existing solution. .

Take a LOS path and a target reflection echo between the second device and the first device, that is, a target object as an example. Table 10 is the table of simulation parameters.

Table 10

Wherein, the bandwidth refers to the bandwidth of the channel, and the pulse repetition period refers to the period of sending the channel detection frame. The angles of the LOS path include θ _t and θ _r , where θ _t is the transmitting angle, and θ _r is the receiving angle, and the θ _t and the θ _r can be shown as θ _t ' and θ _r ' as shown in FIG. 3 .

Wherein, the number of effective paths is the sum of the number of LOS paths and the number of target reflection echoes, so in the example shown in Table 10, the channel includes two effective paths. Since the number of effective paths is equal to the rank of the CSI matrix _H2 , the rank of the CSI matrix is 2, and the V matrix obtained by SVD decomposition of the CSI matrix includes two orthogonal vectors, that is, two column vectors, Denote as v ₁ , v ₂ . The target distance, target angle, target Doppler and other information are extracted from v ₁ and v ₂ respectively. The extraction method is as described above and will not be repeated here.

Exemplary, the final extracted results are shown in Figures 9a to 10f, and Figures 9a to 9c; Figures 10a to 10c are related schematic diagrams _of extracting target distance, target angle, and target Doppler from the column vector v1 . Fig. 9d to Fig. 9f; Fig. 10d to Fig. _10f are related schematic diagrams of column vector v2.

9a to 9f are schematic diagrams of the results extracted from the V matrix solved by the existing solution, and FIGS. 10a to 10f are schematic diagrams of the results extracted from the V matrix solved by the technical solution provided by the embodiment of the present application.

Among them, Fig. 9a, Fig. 9d and Fig. 10a, Fig. 10d are the extracted distance spectra. The vertical axis represents the amplitude, the horizontal axis represents the distance, and the abscissa corresponding to the peak is the target distance or the LOS path distance.

Figure 9b, Figure 9e and Figure 10b, Figure 10e are the extracted angle spectra. Wherein, the vertical axis represents the amplitude, the horizontal axis represents the emission angle, and the abscissa corresponding to the peak is θ _t in the target angle or θ _t in the LOS radius angle.

Figure 9c, Figure 9f and Figure 10c, Figure 10f are the extracted Doppler spectra. The vertical axis represents the amplitude, the horizontal axis represents Doppler, and the horizontal axis corresponding to the peak is the target Doppler or the Doppler corresponding to the LOS path.

It can be seen from FIG. 9a to FIG. 10f that the technical solution provided by the embodiment of the present application can effectively extract the attribute information of the target object, but the existing technical solutions cannot achieve this effect. For example: the abscissa in Figure 10a is 15m, which is the LOS path distance; the corresponding abscissa in Figure 10d is 45m, which is the target distance. However, the abscissa in FIG. 9a and FIG. 9d does not correspond to the target distance and/or LOS path distance in Table 10 above. The target angle and target Doppler are similar, so we will not give examples one by one.

Therefore, it can be seen from the above simulation results that when the number of target objects and LOS paths is smaller than the dimension of the channel matrix, the technical solution provided in the embodiment of the application solves the obtained V matrix, and each column vector corresponds to a target object , which can effectively extract the attribute information of the target object.

The above simulation results are described using one target object as an example. The following description will be made by taking the second device and the first device having one LOS path and two target reflection echoes, that is, two target objects as an example. Table 11 is the table of simulation parameters.

Table 11

Wherein, for the introduction of each parameter in Table 11, please refer to the relevant introduction in Table 3, which will not be repeated here.

As shown in Table 11, at this time, the channel includes three effective paths, the rank of the CSI matrix H ₂ is 3, and the V matrix obtained by performing SVD decomposition on the H ₂ includes three column vectors, denoted as v ₁ , v ₂ , and v ₃ . Information such as target distance, target angle, and target Doppler are extracted from v ₁ , v ₂ , and v ₃ respectively.

Exemplarily, the final extracted results are as shown in Figure 11a to Figure 12i, as shown in Figure 11a to Figure 11c, and Figure 12a to Figure 12c are all extracted from the column vector _v1 target distance, target angle, target Doppler Related diagrams. Fig. 11d to Fig. 11f, Fig. 12d to Fig. _12f are all related schematic diagrams of the column vector v2. Fig. 11g to Fig. 11i, Fig. 12g to Fig. 12i are schematic diagrams related to the column vector _v3 .

Figures 11a to 11i are schematic diagrams of the results extracted from the V matrix solved by the existing solution, and Figures 12a to 12i are schematic diagrams of the results extracted from the V matrix solved by the technical solution provided by the embodiment of the present application.

Among them, Fig. 11a, Fig. 11d, Fig. 11g and Fig. 12a, Fig. 12d, Fig. 12g are the extracted distance spectra. The vertical axis represents the amplitude, the horizontal axis represents the distance, and the abscissa corresponding to the peak is the target distance or the LOS path distance.

Figure 11b, Figure 11e, Figure 11h and Figure 12b, Figure 12e, Figure 12h are the extracted angle spectra. The vertical axis represents the amplitude, the horizontal axis represents the emission angle, and the abscissa corresponding to the peak is θ _t in the target angle or θ _t in the LOS radius angle.

Figure 11c, Figure 11f, Figure 11i and Figure 12c, Figure 12f, Figure 12i are the extracted Doppler spectra. The vertical axis represents the amplitude, the horizontal axis represents Doppler, and the horizontal axis corresponding to the peak is the target Doppler or the Doppler corresponding to the LOS path.

The simulation results shown in FIG. 11a to FIG. 12i further verify that the technical solution provided by the embodiment of the present application can effectively extract the attribute information of the target object.

The foregoing mainly introduces the solutions provided by the embodiments of the present application from the perspective of interaction between each network element. It can be understood that each network element, such as the first device and the second device, includes a corresponding hardware structure and/or software module for performing each function in order to realize the above functions. Those skilled in the art should easily realize that the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

The embodiment of the present application may divide the device into functional modules according to the above method example, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. It should be noted that the division of modules in the embodiment of the present application is schematic, and is only a logical function division, and there may be other division methods in actual implementation. The following is an example of dividing each functional module corresponding to each function:

As shown in FIG. 13 , it is a communication device provided in the embodiment of this application.

In a possible example, the communications apparatus is a first device, and the communications apparatus includes a transceiver unit 1301 and a processing unit 1302 .

The transceiver unit 1301 is configured to receive at least one channel detection frame from the second device. The processing unit 1302 is configured to determine at least one first channel state information CSI matrix H ₁ according to at least one channel sounding frame, where H ₁ is used to indicate a channel state, and the channel sounding frame corresponds to H ₁ one by one. The dimension of H ₁ is N _r ×N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the communication device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , K All are positive integers. The processing unit 1302 is further configured to perform eigenvalue decomposition on the covariance matrix R _HH _of _H2 to obtain the eigenvector matrix U and the eigenvalue matrix Σ; wherein, _H2 is determined according to H1, and _H2 is the corresponding subcarrier CSI matrix. The processing unit 1302 is further configured to determine a second CSI matrix V corresponding to H ₁ according to H ₂ , U, and Σ. The transceiver unit 1301 is further configured to feed back at least one V corresponding to at least one H ₁ to the second device, and the at least one V is used to determine attribute information of the target object.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

In one possible design, a column vector in V corresponds to a target object.

In a possible design, the transceiving unit 1301 is further configured to receive at least one trigger frame from the second device, and the at least one trigger frame is used to instruct the first device to determine V according to H ₂ , U, and Σ.

In another possible example, the communication device is a second device, and the communication device includes a transceiver unit 1301 .

The transceiver unit 1301 is configured to send at least one channel detection frame to the first device. The transceiver unit 1301 is further configured to receive at least one second CSI matrix V corresponding to at least _one H1 from the first device, at least one V is used to determine the attribute information of the target object, and at least _one H1 is determined according to at least one channel detection frame, H ₁ is used to indicate the channel state, and the channel detection frame corresponds to H ₁ one by one. _The dimension of H1 is N _r ×N _t ×K, N _t is the number of antennas of the second device, N _r is the number of antennas of the first device, K is the number of subcarriers carrying channel sounding frames, N _t , N _r , K are all positive integers. V corresponding to H ₁ is determined by H ₂ , U and ∑, U is the eigenvector matrix of the covariance matrix R _HH of H ₂ , ∑ is the eigenvalue matrix of R _HH , H ₂ is determined according to H ₁ , and H ₂ is any one The CSI matrix corresponding to the subcarrier.

Optionally, the communications apparatus may further include a processing unit 1302, where the processing unit 1302 is configured to generate at least one channel sounding frame.

In one possible design, R _HH satisfies:

is the conjugate transpose matrix of _H2 .

In one possible design, a column vector in V corresponds to a target object.

In a possible design, the transceiver unit 1301 is further configured to send at least one trigger frame to the first device, where the at least one trigger frame is used to instruct the first device to determine V according to H ₂ , U, and Σ.

The communication device provided by the above-mentioned embodiments of the present application can be implemented in various product forms. For example, the communication device can be configured as a general-purpose processing system; for another example, the communication device can be implemented by a general bus architecture; For another example, the communication device may be implemented by an application specific integrated circuit (ASIC). Several possible product forms of the communication device described in the embodiments of the present application are provided below. It should be understood that the following product forms are only examples and do not limit the possible product forms of the communication device described in the embodiments of the present application.

FIG. 14 is a result diagram of possible product forms of the communication device described in the embodiment of the present application.

As a possible product form, the communication device described in the embodiment of the present application may be a communication device.

When the communication device is the first device, the communication device includes a processor 1401 and a transceiver 1402 . Optionally, the communication device further includes a memory 1403 . The processor 1401 is configured to execute step S402, step S403, and step S404 in FIG. 4, and/or other processing operations that need to be executed by the first device in this embodiment of the present application. The transceiver 1402 is configured to perform step S401 and step S405 in FIG. 4 , and/or other transceiving operations that need to be performed by the first device in this embodiment of the present application.

When the communication device is the second device, the communication device includes a transceiver 1402 . Optionally, the communication device further includes a processor 1401 and a memory 1403 . The processor 1401 is configured to generate at least one channel sounding frame, and/or other processing operations that need to be performed by the second device in this embodiment of the present application. The transceiver 1402 is configured to perform step S401 and step S405 in FIG. 4 , and/or other transceiving operations that need to be performed by the second device in this embodiment of the present application.

As another possible product form, the communication device described in the embodiment of the present application may also be implemented by a general-purpose processor or a special-purpose processor, which is commonly called a chip.

When the chip is the first device, the chip includes: a processing circuit 1401 and a transceiver pin 1402 . The processing circuit 1401 is configured to execute step S402, step S403, and step S404 in FIG. 4, and/or other processing operations that need to be executed by the first device in the embodiment of the present application. The transceiving pin 1402 is used to perform step S401 and step S405 in FIG. 4 , and/or other transceiving operations that need to be performed by the first device in the embodiment of the present application.

When the chip is the second device, the chip includes: a transceiver pin 1402 . Optionally, the chip may further include a processing circuit 1401 . The processing circuit 1401 is configured to generate at least one channel sounding frame, and/or other processing operations that need to be performed by the second device in this embodiment of the present application. The transceiving pin 1402 is used to perform step S401 and step S405 in FIG. 4 , and/or other transceiving operations that need to be performed by the second device in the embodiment of the present application.

As another possible product form, the communication device described in the embodiment of the present application may also be implemented using the following circuits or devices: one or more field programmable gate arrays (field programmable gate array, FPGA), programmable logic A programmable logic device (PLD), controller, state machine, gate logic, discrete hardware components, any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.

Optionally, the embodiments of the present application further provide a computer program product carrying computer instructions, and when the computer instructions are run on the computer, the computer is made to execute the method described in the foregoing embodiments.

Optionally, an embodiment of the present application further provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and when the computer instructions are run on a computer, the computer executes the method described in the above-mentioned embodiments.

Those skilled in the art can understand that: in the above embodiments, all or part of them can be implemented by software, hardware, firmware or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions according to the embodiments of the present application will be generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center via wired (such as coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device including a server, a data center, and the like integrated with one or more available media. The available medium may be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (such as a solid state disk (Solid State Disk, SSD)) wait.

In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or modules may be in electrical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple devices. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Through the above description of the implementation, those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary general-purpose hardware, of course, it can also be implemented by hardware, but in many cases the former is a better implementation . Based on this understanding, the essence of the technical solution of this application or the part that contributes can be embodied in the form of software products, and the computer software products are stored in readable storage media, such as computer floppy disks, hard disks or optical disks etc., including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute the methods described in the various embodiments of the present application.

The above is only a specific implementation of this application, but the protection scope of this application is not limited thereto, and changes or replacements within the technical scope disclosed in this application should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

A communication method, characterized in that the method comprises:

the first device receives at least one channel sounding frame from the second device;

The first device determines at least one first channel state information CSI matrix H 1 according to the at least one channel sounding frame, the H 1 is used to indicate the channel state, and the channel sounding frame corresponds to the H 1 one by one; The dimension of H1 is N r ×N t ×K, N t is the number of antennas of the second device, N r is the number of antennas of the first device, and K is the subcarrier carrying the channel detection frame Number, the N t , the N r , and the K are all positive integers;

The first device performs eigenvalue decomposition on the covariance matrix R HH of H2 to obtain the eigenvector matrix U and the eigenvalue matrix Σ; wherein, the H2 is determined according to the H1, and the H2 is any one The CSI matrix corresponding to the subcarrier;

The first device determines the second CSI matrix V corresponding to the H 1 according to H 2 , the U, and the Σ;

The first device feeds back at least one V corresponding to the at least one H 1 to the second device, and the at least one V is used to determine attribute information of the target object.
A communication method, characterized in that the method comprises:

the second device sends at least one channel sounding frame to the first device;

The second device receives at least one second CSI matrix V corresponding to at least one H1 from the first device, the at least one V is used to determine the attribute information of the target object, and the at least one H1 is based on the at least one A channel detection frame is determined, the H 1 is used to indicate the channel state, and the channel detection frame corresponds to the H 1 one by one; the dimension of the H 1 is N r ×N t ×K, and N t is the The number of antennas of the second device, N r is the number of antennas of the first device, K is the number of subcarriers carrying the channel sounding frame, the N t , the N r , and the K are all positive integers;

The V corresponding to the H 1 is determined by H 2 , U and Σ, the U is the eigenvector matrix of the covariance matrix R HH of the H 2 , the Σ is the eigenvalue matrix of the R HH , and the H 2 is determined according to the H 1 , and the H 2 is a CSI matrix corresponding to any subcarrier.
method according to claim 1 or 2, is characterized in that, described R HH satisfies:
said
is the conjugate transpose matrix of H2 .
The method according to any one of claims 1-3, wherein the column vector u s in the U and the column vector v s in the V satisfy the following conditions:

Wherein, the σ s is the singular value corresponding to the v s , the σ s is the arithmetic square root of the corresponding eigenvalue in the Σ, s is an integer from 1 to m, and the m is the column in the V The number of vectors, the m is a positive integer.
The method according to any one of claims 1-4, wherein the condition for obtaining the column vector in U comprises: assigning the a-th element in each column vector in U to be b, the a is a positive integer, and b is a real number.
The method according to any one of claims 1-5, wherein the attribute information of the target object includes a target distance, and the target distance is a distance between the target object and the first device, and the sum of distances between the target object and the second device;

Wherein, the target distance is determined by at least two Vs corresponding to one H1.
The method according to any one of claims 1-6, wherein the attribute information of the target object further includes a target angle, and the target angle includes a launch angle between the second device and the target object ;

Wherein, the target angle is determined by a V.
The method according to any one of claims 1-7, wherein the attribute information of the target object further includes target Doppler, and the target Doppler is received by the first device through the target object The difference between the frequency of the channel sounding frame and the frequency at which the second device sends the channel sounding frame;

Wherein, the target Doppler is determined by at least one V corresponding to at least two H 1 .
The method according to any one of claims 1-8, characterized in that one column vector in V corresponds to one target object.
The method according to any one of claims 1, 3-9, wherein after the first device receives at least one channel sounding frame from the second device, the method further comprises:

The first device receives at least one trigger frame from the second device, and the at least one trigger frame is used to instruct the first device to determine the V according to the H 2 , the U, and the Σ.
The method according to any one of claims 2-9, wherein before the second device receives at least one second CSI matrix V corresponding to at least one H1 from the first device, the method further include:

The second device sends at least one trigger frame to the first device, where the at least one trigger frame is used to instruct the first device to determine the V according to the H 2 , the U, and the Σ.
A communication device, characterized by comprising:

a transceiver unit, configured to receive at least one channel sounding frame from the second device;

A processing unit, configured to determine at least one first channel state information CSI matrix H 1 according to the at least one channel sounding frame, the H 1 is used to indicate the channel state, and the channel sounding frame corresponds to the H 1 one by one; The dimension of H1 is N r ×N t ×K, N t is the number of antennas of the second device, N r is the number of antennas of the communication device, and K is the number of subcarriers carrying the channel detection frame , the N t , the N r , and the K are all positive integers;

The processing unit is further configured to perform eigenvalue decomposition on the covariance matrix R HH of H 2 to obtain an eigenvector matrix U and an eigenvalue matrix Σ; wherein, the H 2 is determined according to the H 1 , and the H 2 is the CSI matrix corresponding to any subcarrier;

The processing unit is further configured to determine a second CSI matrix V corresponding to the H 1 according to the H 2 , the U and the Σ;

The transceiving unit is further configured to feed back at least one V corresponding to the at least one H 1 to the second device, and the at least one V is used to determine attribute information of the target object.
A communication device, characterized by comprising:

A transceiver unit, configured to send at least one channel detection frame to the first device;

The transceiver unit is further configured to receive at least one second CSI matrix V corresponding to at least one H1 from the first device, the at least one V is used to determine the attribute information of the target object, and the at least one H1 is based on The at least one channel detection frame is determined, the H 1 is used to indicate the channel state, and the channel detection frame corresponds to the H 1 one by one; the dimension of the H 1 is N r ×N t ×K, N t is the number of antennas of the second device, N r is the number of antennas of the first device, K is the number of subcarriers carrying the channel detection frame, the N t , the N r , and the K are positive integer;

The V corresponding to the H 1 is determined by H 2 , U and Σ, the U is the eigenvector matrix of the covariance matrix R HH of H 2 , the Σ is the eigenvalue matrix of the R HH , and the H 2 Determined according to the H1, the H2 is a CSI matrix corresponding to any subcarrier.
The device according to claim 12 or 13, wherein the R HH satisfies:
said
is the conjugate transpose matrix of H2 .
The device according to any one of claims 12-14, wherein the column vector u s in the U and the column vector v s in the V satisfy the following conditions:

Wherein, the σ s is the singular value corresponding to the v s , the σ s is the arithmetic square root of the corresponding eigenvalue in the Σ, s is an integer from 1 to m, and the m is the column in the V The number of vectors, the m is a positive integer.
The device according to any one of claims 12-15, wherein the conditions for obtaining the column vectors in U include: assigning b to the a-th element in each column vector in the U, the a is a positive integer, and b is a real number.
The apparatus according to any one of claims 12-16, wherein the attribute information of the target object includes a target distance, and the target distance is a distance between the target object and the first device, and the sum of distances between the target object and the second device;

Wherein, the target distance is determined by at least two Vs corresponding to one H1.
The device according to any one of claims 12-17, wherein the attribute information of the target object further includes a target angle, and the target angle includes a launch angle between the second device and the target object ;

Wherein, the target angle is determined by a V.
The device according to any one of claims 12-18, wherein the attribute information of the target object further includes target Doppler, and the target Doppler is received by the first device through the target object The difference between the frequency of the channel sounding frame and the frequency at which the second device sends the channel sounding frame;

Wherein, the target Doppler is determined by at least one V corresponding to at least two H 1 .
The device according to any one of claims 12-19, wherein one column vector in V corresponds to one target object.
The device according to any one of claims 12, 14-20, characterized in that,

The transceiver unit is further configured to receive at least one trigger frame from the second device, the at least one trigger frame is used to instruct the first device to determine the V.
The device according to any one of claims 13-20, characterized in that,

The transceiver unit is further configured to send at least one trigger frame to the first device, where the at least one trigger frame is used to instruct the first device to determine the V.
A communication device, characterized in that the communication device includes a transceiver, and the communication device is configured to implement the communication method according to any one of claims 1-11.
A computer-readable storage medium, characterized in that the computer-readable storage medium includes a computer program or an instruction, and when the computer program or instruction is run on a computer, the computer executes the computer program described in claims 1-11. The communication method described in any one.
A computer program product, characterized in that the computer program product comprises: a computer program or an instruction, when the computer program or instruction is run on a computer, the computer executes any one of claims 1-11 the communication method described.
A chip, characterized in that the chip includes a processing circuit and a transceiver pin, and when an instruction is executed by the processing circuit, the chip executes the communication method according to any one of claims 1-11.